1. Technical Field
The present disclosure relates to a display panel. More particularly, the present disclosure relates to a gate driver in a display panel
2. Description of Related Art
In recent years, a liquid crystal display (LCD) has been commonly used as a display device because of its capability of displaying images with high quality while using little power consumption.
For the LCD, a display panel of the LCD is driven by a driver circuit, and the driver circuit includes a gate driver circuit and a source driver circuit, in which the gate driver circuit generates gate signals sequentially transmitted on gate lines, thereby sequentially activating pixel units row by row, and the source driver circuit generates data signals transmitted through data lines to the pixel units, such that images can be displayed on the display panel.
The aforementioned gate driver circuit may be implemented by various types of circuit, in which one of those types of circuits is implemented in a form of gate driver on array (GOA) on the display panel, i.e., the gate driver circuit is formed on a glass substrate of the LCD panel. In such type of gate driver circuit, devices (e.g., transistor switch) can be made of a material such as amorphous silicon (a-Si) or Indium-Gallium-Zinc Oxide (IGZO). However, when the devices made of the material such as amorphous silicon or Indium-Gallium-Zinc Oxide are utilized in the gate driver circuit, the devices usually operate with leakage currents, and thus an output signal has ripples therein. In other words, significant interference noises appear in the output signal and thus the power consumption increases. Moreover, if the ripples are desired to be reduced, an additional voltage stabilizing circuit has to be used to increase the capability of voltage stabilization. Nonetheless, more power consumption and circuit layout areas are needed. A typical gate driver circuit taken as an example is described below.
FIG. 1 is a circuit diagram illustrating a gate driver unit in a conventional gate driver. As shown in FIG. 1, in the condition that the gate driver unit 100 is activated, a transistor switch M1 operates according to an input signal IN1, such that a node Q has a corresponding voltage level, thus resulting in that a transistor switch M7 operates correspondingly and a gate signal G[N] is therefore generated and outputted to a gate line. Then, a voltage stabilizing circuit (e.g., transistor switches M5 and M6) stabilizes the outputted gate signal G[N].
However, when the gate driver unit 100 is activated, leakage currents are generated at the node Q by the transistor switches M5 and M6, e.g., a leakage current path is formed between the node Q and the transistor switch M1 due to device characteristics. Furthermore, when the gate driver unit 100 is deactivated, the transistor switches operate with a pre-determined voltage (e.g., Vgs=0 V). Since the transistor switches (e.g., M1-M7) are made of the material such as amorphous silicon or indium-Gallium-Zinc Oxide, the characteristic of the device itself causes the leakage current to become large, such that the ripple effect is significant and the additional power consumption increases significantly.